l-Histidine enhances stability of hemoglobin concentrates by coordinating with free iron

• Published in: Food research international Vol. 62; pp. 637 - 643
• Main Authors: Zhou, Cunliu, Ye, Huiqiong, Nishiumi, Tadayuki, Qin, Hao, Chen, Conggui
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-08-2014; Elsevier
• Subjects: Biological and medical sciences; Coiling; Concentrates; Coordination; Food industries; Free iron; Fundamental and applied biological sciences. Psychology; Hemoglobin; Hemoglobin concentrates (HbC); Iron; l-Histidine (L-His); Oxyhemoglobin; Spectra; Stability; Transformations; l-Histidine (L-His); Stability; Free iron; Coordination; Hemoglobin concentrates (HbC); Histidine; Aminoacid; Quality; Hemoglobin; Iron; Concentrate; L-Histidine (L-His)
• ISSN: 0963-9969; 1873-7145
• DOI: 10.1016/j.foodres.2014.04.018

The objective of this investigation was to evaluate the effects of l-histidine on the stability of porcine hemoglobin concentrates during storage. The results indicated that the addition of l-histidine increased the oxyhemoglobin content and a* values but decreased the methemoglobin content and free iron content (P<0.05) during storage. The addition of iron cation decreased both the oxyhemoglobin content and a* values but increased both the methemoglobin content and free iron concentration (P<0.05). CD spectra revealed that the free iron content induced the transformation of the hemoglobin secondary structure from an α-helix (close structure) to a β-pleated, β-turn, and random coil arrangement (loose structure), while l-histidine weakened this behavior of the free iron. Infrared spectra demonstrated that the l-histidine coordinated with the free iron (Fe2+ or Fe3+) to give the corresponding complex at 25°C and pH7.3. Therefore, l-histidine enhanced the stability of hemoglobin concentrates by coordinating with free iron.
•L-His prevented effectively porcine HbC from oxidation and discolor during storage.•L-His weakened that Fe3+ induces transformation of Hb from α-helix to β-pleated.•L-His coordinated with Fe2+ (or Fe3+) to give the corresponding complexes.•It is proposed that L-His enhances stability of HbC by coordinating with free iron.